The invention relates generally to lightning detection systems, and more particularly, to lightning detection systems for wind turbines.
Lightning is a random phenomenon in nature. As will be appreciated, lightning parameters vary depending on geographical conditions and the nature of lightning in terms of intensity and impact on an object. Wind turbines, in particular, are generally subjected to a high risk of lightning strikes as they are preferentially placed at high and windy locations in order to achieve high productivity.
Currently, there exist several lightning detection systems for use with wind turbines. These techniques may broadly be classified into two categories. In a first category of lightning detection systems the detection system includes magnetic cards positioned in various parts of a wind turbine blade to detect lightning current passing through. After a lightning impact, the magnetic cards are read out manually by a card reader unit to measure a peak value of current. However, the system is unable to detect the number of lightning sequences striking a wind turbine between periods of two magnetic card readings.
Additionally, in a second category of lightning detection systems, the lightning detection systems include small antennas fixed on a body of a wind turbine tower. The antennas are used to detect lightning currents and magnetic fields that pass through the wind turbine tower. Signals from the antennas are transformed from an electrical signal to an optical signal and are communicated to a control box via an optical fiber. Further, an output of the control box is indicative of a lightning impact. Unfortunately, in most cases, the system has to be reset by an acknowledgement signal. Moreover, an affected blade cannot be automatically identified via use of these lightning detection systems.
Furthermore, conventional lightning detection systems, including the abovementioned two categories of lightning detection systems typically require installation of specialized sensors such as small antennas, magnetic cards, and the like for detection of a lightning strike. The installation of supplementary sensors thus results in additional cost for detection of the lightning strike. Moreover, conventional lightning detection systems are configured to register occurrence of lightning events. However, these conventional systems fail to register lightning event parameters or localization of impact. Therefore, a need exists for an improved lightning detection system that may address one or more of the problems set forth above.